Just my .02 here. From what I have read the Carter seems to be a good pump. Mounting the Carter down on the frame might be simpler than mounting the Facet in the engine compartment. After making a larger bracket to support both coolant filter and Facet pump, relocating the coffee can, and the additional wiring from pump and 3g alt upgrade my passenger fender is damn crowded. If my Facet were to fail prematurely I would be tempted to go with a "pusher" pump mounted on the frame just to free up some space. The other factor I would consider is replacement pump availability. Personally I would just buy two of whatever you decide to go with. With only one vehicle I can't afford downtime while twiddling my thumbs waiting for a new pump in the mail. Missed work quickly costs me more than buying parts before I need them. Again, just my .02.
The Facet is relatively quiet and I never hear it while driving. The extra filter in the fuel bowl is cool too.